Soy Protein Hydrolysates Research Articles

Generation of antioxidant peptides from soy protein isolate through psychrotrophic Chryseobacterium sp. derived alkaline broad temperature active protease

Antioxidant peptides confer numerous health benefits. Unexplored niches provide bioprospection opportunities for potential protease producing microorganisms that are useful in releasing antioxidant peptides from protein sources impacting human health. A cold-adapted bacterium Chryseobacterium polytrichastri ERMR1:04 produced an extracellular protease enzyme optimally at 20 °C, pH 8 with 1.25 g/100 mL skim milk inducer. The purified 22.24 kDa protease was active over a broad temperature 5–65 °C (optimum at 37 °C) and pH 6–10 (optimum at pH 8) range, inhibited by EDTA and 1, 10-phenanthroline, enhanced by Ca2+, Mn2+ and hexane, and retained its activity with surfactants and detergents. ERMR1:04 protease-mediated hydrolysis of soy protein generated antioxidant peptides of <6 kDa, with successful identification, showing radical scavenging activities of 77% DPPH, 96% ABTS, 93% ferrous ion chelation, and Abs700 0.159 for reducing power assay. Such promising properties qualify the ERMR1:04 protease as a potent catalyst for high-value functional food production.

Inhibitory effects of soy protein and its hydrolysate on the degradation of anthocyanins in mulberry extract

The inhibitory effects of soy protein (SP) and soy protein hydrolysate (SPH) on the changes in color and anthocyanin content in mulberry anthocyanin extract (MAE) during storage (42 °C/5 d) were investigated at pH 6.3. Fluorescence spectroscopy, circular dichroism (CD), and Fourier-transform infrared (FT-IR) spectroscopy were used to study the interaction between SP/SPH and cyanidin-3-O-glucoside (C3G), the major anthocyanin in MAE. The results showed that SP and SPH inhibited the degradation of color and anthocyanin content in MAE and extended its half-life (t1/2) 0.15 and 2.25 times, respectively. Additionally, the protection provided with SPH was better than with SP. The fluorescence analysis showed that SP and SPH interacted with C3G mainly through hydrophobic and electrostatic interactions, respectively, and the binding affinity of SPH for C3G was greater than that of SP. The inhibitory effect of SP/SPH on the degradation of MAE might be positively correlated with the SP/SPH–C3G interactions. FT-IR and CD results showed that complexation with C3G changed the secondary structure of SP/SPH, which was reflected by a decrease in the β-sheet content and increases in β-turns and random-coils. These results showed the efficacy of SP/SPH for preserving anthocyanins and developing functional, natural colorants for applications within the food industry.

The influence of soy protein hydrolysate (SPH) addition to infant formula powder on Streptococcus thermophilus proliferation and metabolism

Nowadays, more and more infants are getting allergic to cow’s milk protein, so it is urgent to search for infant formula powder with milk protein alternatives. In the present work, soy protein hydrolysate (SPH) was added to protein-free infant formula powder and the effects of SPH addition on proliferation and metabolism of Streptococcus thermophilus were studied. Compared with commercially available infant formula powder (CK) and protein-free milk powder (BK), the infant formula powder with 20% SPH significantly enhanced the proliferation of S. thermophilus in MRS medium, resulting in a higher cell density and greater viable counts. Moreover, the influence of SPH on the metabolism of S. thermophilus was investigated by analyzing the content of seven organic acids and H2O2 in the medium. The higher content of organic acids and H2O2 is consistent with the stronger antibacterial activity to Escherichia coli. As a consequence, the addition of SPH to infant formula powder can effectively promote the growth of probiotics and SPH may be a promising protein alternative in the infant formula powder.

ГЕМАТОЛОГИЧЕСКИЕ И БИОХИМИЧЕСКИЕ ПОКАЗАТЕЛИ КРОВИ КУР-НЕСУШЕК ПРИ ИСПОЛЬЗОВАНИИ КОРМОВОЙ ДОБАВКИ РАСТИТЕЛЬНОГО ПРОИСХОЖДЕНИЯ

The article presents the results of the use of soy protein hydrolysate in combination with vitamins and microelements «Abiotonic» on laying hens of the cross «Hayseks brown» at the rate of 1 ml/kg of live weight. In order to determine the efficiency of the feed additive, indicators of the clinical status of birds were studied, biochemical and clinical blood tests were carried out. It was found that the feed additive «Abiotonic» in a dose of 1 ml/kg of live weight of hens does not have a negative effect on the physiological indicators of birds. The results of blood tests make it possible to talk about a reliable stimulating effect of feed additives on the metabolic processes, increasing the indicators characterizing hematopoiesis. Accordingly, the feed additive «Abiotonic» can be recommended for use in birds during the period of active growth and development of the organism.

Novel Zn-Binding Peptide Isolated from Soy Protein Hydrolysates: Purification, Structure, and Digestion.

In this study, a novel Zn-binding peptide, Lys-Tyr-Lys-Arg-Gln-Arg-Trp (KYKRQRW), was purified and identified from soy protein isolate hydrolysates (SPIHs). The Zn-binding peptide exhibited improved Zn-binding capacity (83.21 ± 2.65%) than SPIH solutions. CD, NMR, and Fourier transform infrared spectroscopy were used to confirm the complexation between Zn and the peptide. The results showed that the Zn-binding peptide formed a folding structure with part of the β-sheet (29.3-13.4%) turning into random coils (41.7-57.6%) during complexation. It was further proved that the binding sites were located at the oxygen atoms on the carboxyl group of the Trp side chain and nitrogen atoms on the amino group of the Lys side chain. Moreover, the Zn-peptide complex exhibited increased solubility than ZnSO4 during simulated gastrointestinal digestion. This study highlighted that the novel soy peptide possessed a strong zinc chelate rate and had a positive effect on the gastrointestinal stability of Zn which could be utilized as a functional ingredient in future.

Impact of Peptidase Activities on Plant Protein Hydrolysates Regarding Bitter and Umami Taste.

The aim of this study was to investigate six food-grade peptidase preparations, namely, Flavourzyme 1000L, Protease P "Amano" 6SD, DeltazymAPS-M-FG, Promod278, ProteAX-K, and Peptidase R, regarding their use for the hydrolysis of soy, pea, and canola protein. The relationship between the specific peptidase activities and, first, the degree of hydrolysis, second, the free amino acid profiles of the hydrolysates, and, third, the corresponding taste of the hydrolysates was analyzed using a random forest model. The taste attributes bitter and umami were of special interest. The peptidase ProteAX-K was the biocatalyst most suited for the high umami and low bitter taste of the plant-based protein hydrolysates based on the experimental results and the random forest model.

Emulsifying and emulsion stabilizing properties of soy protein hydrolysates, covalently bonded to polysaccharides: The impact of enzyme choice and the degree of hydrolysis

Emulsifying and emulsion stabilizing properties of fragments, derived from vegetable proteins (soy protein isolate) and covalently linked to maltodextrin have been studied. The dual role of the degree of hydrolysis (DH) in improving the solubility of soy protein isolate (SPI) on one hand and difficulties of linking hydrolysates to polysaccharide on the other, have been highlighted. The findings have been compared to results obtained for whey protein isolate (WPI) fragments, undergoing the same enzymatic fragmentation and subsequent Maillard reaction. All experiments were conducted with two very different enzymes. Trypsin is rather selective of peptide bonds it cleaves, while alcalase is less specific. At the same DH, the actions of these two enzymes on the behaviour of the resulting conjugates were found to be broadly similar for the whey protein hydrolysates. In contrast, the trypsin generated soy protein fragments showed distinctly superior emulsifying properties than those produced by alcalase. These differences were related to the physical form of SPI existing as small colloidal aggregates in solution at the time of hydrolysis, whereas WPI was present as a molecularly well-dissolved protein. It is shown that, in realizing the best emulsion stabiliser, the improved solubility as a result of a higher level of hydrolysis is offset by the deterioration of the surface functionality of polypeptides due to further fragmentation. This leads to an optimum value for the DH of vegetable proteins for synthesising the most suitable Maillard based emulsifiers. For commercial SPI used in this study this was found to be around 8%.

Complexation between soy peptides and epigallocatechin-3-gallate (EGCG): Formation mechanism and morphological characterization

This study investigated the feasibility of using epigallocatechin-3-gallate (EGCG) as a carrier to interact with and precipitate peptides from soy protein hydrolysate water. EGCG was added to soy peptides, resulting in the formation of aggregates that precipitated upon centrifugation. The recovery efficiencies of peptides were evaluated at both an acidic pH of 4.5 and a neutral pH of 7.0 with varying concentrations of EGCG. Results showed that the peptide recovery increased with increasing concentrations of EGCG. The maximum recovery of peptides was 57.17%, at pH 4.5 and an EGCG/peptide ratio of 0.40. Further increases in EGCG concentrations did not result in any changes to peptide recovery, suggesting that the interaction between EGCG and peptide followed a Poisoned Growth Model. The peptides recovered by EGCG have much better solubility than acid precipitated peptides. This work establishes the feasibility of, and methodology for, recovering peptides from water solution using EGCG as an efficient carrier.

Application of high-GABA producing Lactobacillus plantarum isolated from traditional cabbage pickle in the production of functional fermented whey-based formulate

In this study, a fermented whey-based formulate with enhanced levels of gamma aminobutyric acid (GABA) was produced by using a selected lactic acid bacteria isolated from traditional cabbage pickle. 16S rRNA gene sequencing resulted in identification of high GABA-producing isolate as Lactobacillus plantarum which was used as single or co-culture with Lactococcus lactis subsp. lactis (a proteolytic strain from the microbial bank). The isolated L. plantarum showed higher proteolytic, acidification and GABA-producing activity in cheese whey compared to Lc. lactis Subsp. lactis. However, the highest concentration of GABA (365.6 mg/100 mL) was found in the samples fermented using co-cultures of these strains. Moreover, addition of soy protein hydrolysate (SPH) to whey resulted in a significant enhancement in GABA concentration in the final product upon fermentation. Moreover, in the co-cultured sample containing higher amount of SPH, the lower fermentation time was observed. The results of this study showed that L. plantarum isolated from cabbage pickle is a good candidate to be used as p starter culture to manufacture a novel functional whey formulate enriched with GABA.

Soybean Protein Extraction by Alcalase and Flavourzyme, Combining Thermal Pretreatment for Enteral Feeding Product

Soybean is one of the essential ingredients when formulating a tube feeding formula. In this study, we initially focused on determining which enzyme is suitable for hydrolyzing soy and comparing the soy protein enzymatic hydrolysis of three different enzymes at the same enzyme content: Flavourzyme, Protamex, and Alcalase. The result showed that Flavourzyme attained the highest soluble protein recovery efficiency (SPRE). Secondly, the study determined the effect of thermal treatment conditions such as thermal treatment duration, and then it showed that when combining the thermal treatment and enzymatic hydrolysis, the yield reached (61.44 ± 0.22)%, which was much higher than only using enzymatic hydrolysis (52.57 ± 0.27)%. Next, optimizing the enzymatic hydrolysis (combining thermal treatment) using Flavourzyme and Alcalase, Flavourzyme achieved (62.47 ± 0.12)%, while Alcalase attained (41.32 ± 0.13)%. The soy hydrolyzate using Flavourzyme achieved an average molecular size of 3.19 kDa at the following optimizing conditions: enzyme concentration, 16.09 U·g−1; pH, 7.02; temperature, 45.8 °C; and beans/water ratio, 1:3. In contrast, when using Alcalase, the soy hydrolyzate achieved an average molecular size of 1.52 kDa at the following optimizing conditions: enzyme concentration, 28.01 U·g−1; pH, 7.2; temperature, 56.5 °C; beans/water ratio, 1:4.6. Soy protein hydrolyzate of suitable viscosity and particle size flow through the inhaler with branched-chain amino acids achieved a BCAA (Branched Amino Acid) ratio of 2:1:1 for Alcalase and 4:1:1 for Flavourzyme. Soybean hydrolyzate using both enzymes attained a high SPRE and was suitable for the digestive ability of patients recovering from surgery. Soy protein is divided into amino acids, di- and tri-amino acids, and peptides to create a soluble protein source that helps feed patients with a sonde tube easily. In addition, the molecular weight of peptides will reduce viscosity significantly when passing through a sonde tube, preventing tube congestion.

Optimization of enzymatic hydrolysis conditions for producing soy protein hydrolysate with maximum lipolysis-stimulating activity

The optimum hydrolysis conditions of 2.5% (w/v) soy protein isolate (SPI) with 1% (w/w of SPI) Flavourzyme® for increasing glycerol release in mature 3T3-L1 adipocytes were investigated by response surface methodology (RSM). Higher glycerol release indicated higher lipolysis-stimulating activity. The independent variables were hydrolysis time (HT) 19.2-220.8 min, pH 5.32-8.68 and reaction temperature (RT) 33.2-66.8°C. Based on the response surface and contour plots, the optimum hydrolysis of SPI with Flavourzyme® for maximizing the glycerol release in the cells occurred at pH = 7.12, RT = 48.77°C and HT = 124.85 min. The F-value for lack of fit was not significant (p > 0.05), so the second order model was appropriate for describing the response surface. In addition, the model had a satisfactory coefficient of R 2 (= 0.935) and was verified experimentally.

Ultrasound driven conformational and physicochemical changes of soy protein hydrolysates

The effect of ultrasound on the conformational and physicochemical properties of soy protein isolate hydrolysates (SPHs) was investigated. SPHs were prepared at hydrolysis times of 20 min, 60 min, and 180 min, then treated with ultrasound for 10 min, 20 min, and 30 min at a frequency of 20 kHz and output powers of 150 W and 450 W. The structural properties and antioxidant capacities of the aqueous layer of SPHs (ASPHs) after sonication were evaluated by Fourier-transform infrared spectroscopy (FTIR), intrinsic fluorescence, DPPH radical scavenging activity assays, and microscopy observations. Results obtained showed that ultrasound treatment significantly disrupted the peptide aggregates formed during protein hydrolysis. The protein solubility was significantly increased after sonication (by up to 18.33%), as did the percentage of proteins with MW < 1 kDa in ASPHs. The antioxidant capacity of ASPHs also increased, as measured by DPPH assay. FTIR analysis of ASPHs indicated that the protein secondary structures were different, with an increase in β-sheet and a decrease in α-helix and β-turn. Furthermore, the changes in fluorescence spectra of ASPHs showed the transition of protein tertiary structure with a greater exposure of Trp residues in the side chains. Scanning electron microscope (SEM) and atomic force microscope (AFM) observations of the morphological structure of ASPHs further confirmed the significant effect of sonication on disrupting peptide aggregates. In conclusion, ultrasound can be used as an efficient treatment to promote the solubility of protein hydrolysates.

Rheological Characterization of a Wood Adhesive Based on a Hydrolyzed Soy Protein Suspension

Soy protein (SP) is a promising raw material for the development of renewable and environmentally friendly adhesives. This work aims to study the effect of protein denaturation and/or hydrolysis on the rheology of a soy protein isolate (SPI) suspension. Four stages of chemical modification of SPI were evaluated: unmodified (U), denatured (D), partially hydrolyzed (PH) and fully hydrolyzed (H). Fourier-transform infrared spectroscopy (FTIR) and sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE) confirmed that polypeptides with high molecular weight were fully fragmented into smaller ones. Rheological analysis showed that U behaves as a gel-like material while PH and H act as viscous-like materials. Hydrolysis caused a significant decrease in the viscosity, even for suspensions with high solid content. Furthermore, comparing U and H, the viscosity at high shear strength dropped 65% with an increase of 219% in the solid content. The shear strength of the adhesives can be increased through two strategies: crosslinking with epoxy resin and the addition of different reinforcements. Considering suspension H as reference, the addition of 20% epoxy resin and 5% montmorillonite clay caused an increase in the shear strength of almost 39%. These results could contribute to the development of high solid content SP-based adhesive with desirable rheological properties and zero formaldehyde emission.

Biochemical Properties of a Partially Purified Protease from Bacillus sp. CL18 and Its Use to Obtain Bioactive Soy Protein Hydrolysates.

Microbial proteases are relevant biocatalysts with diverse applications. Production of protein hydrolysates is recently focused, since they might display biological activities. Therefore, the extracellular protease from Bacillus sp. CL18 was partially purified through ammonium sulfate precipitation (25-50% saturation) and gel filtration chromatography, with a 60.7-fold purification (40,593 U/mg protein) and 21.3% recovery. The partially purified protease (PPP) was characterized as a serine protease, with optimal activity at 51-59 °C and pH 7.4-8.8 and low thermal stability. Thermal inactivation followed first-order kinetics. PPP depended on Ca2+ for higher thermal stability, depicted by increases in half-lives (t1/2), activation energy (Ea), and free energy (ΔG#) for kinetic inactivation. PPP preferentially hydrolyzed casein > soy protein isolate (SPI) >>> keratinous materials. SPI hydrolysis by PPP was further investigated, and the obtained hydrolysates exhibited increased in vitro bioactivities. Hydrolysates displayed antioxidant capacities through the scavenging of synthetic organic radicals and Fe3+-reducing ability. In addition, hydrolysates inhibited the activities of dipeptidyl peptidase IV (DPP IV) and angiotensin-converting enzyme (ACE), suggesting antidiabetic and antihypertensive potentials, respectively. From its biochemical properties, PPP might be used to produce protein hydrolysates with multifunctional bioactivities. Both PPP and SPI hydrolysates can find applications in food biotechnology.

Optimization of the Emulsifying Properties of Food Protein Hydrolysates for the Production of Fish Oil-in-Water Emulsions.

The incorporation of lipid ingredients into food matrices presents a main drawback—their susceptibility to oxidation—which is associated with the loss of nutritional properties and the generation of undesirable flavors and odors. Oil-in-water emulsions are able to stabilize and protect lipid compounds from oxidation. Driven by consumers’ demand, the search for natural emulsifiers, such as proteins, is gaining much interest in food industries. This paper evaluates the in vitro emulsifying properties of protein hydrolysates from animal (whey protein concentrate) and vegetal origin (a soy protein isolate). By means of statistical modelling and bi-objective optimization, the experimental variables, namely, the protein source, enzyme (i.e., subtilisin, trypsin), degree of hydrolysis (2–14%) and emulsion pH (2–8), were optimized to obtain their maximal in vitro emulsifying properties. This procedure concluded that the emulsion prepared from the soy protein hydrolysate (degree of hydrolysis (DH) 6.5%, trypsin) at pH 8 presented an optimal combination of emulsifying properties (i.e., the emulsifying activity index and emulsifying stability index). For validation purposes, a fish oil-in-water emulsion was prepared under optimal conditions, evaluating its physical and oxidative stability for ten days of storage. This study confirmed that the use of soy protein hydrolysate as an emulsifier stabilized the droplet size distribution and retarded lipid oxidation within the storage period, compared to the use of a non-hydrolyzed soy protein isolate.

Control of Initiation and Aggressiveness of DMBA‐Induced Breast Cancer in Rats by Dietary Consumption of Hinute‐AM.

We reported earlier that the consumption of soy protein controlled not only the proliferation of dimethylbenz [a] anthracene (DMBA)‐induced breast cancer in rats but also its aggressiveness. Soy protein is hydrolyzed in the gut to small peptides which are easily absorbed and are involved in various cellular functions. Fuji Oil Company, Osaka, Japan, has commercially marketed a soy protein hydrolysate, termed Hinute‐AM, composed of primarily di‐ and tripeptides, to be used as a health food, and it has anti‐inflammatory property. The purpose of the present study was to investigate whether dietary intake of Hinute‐AM can delay the development of DMBA‐induced breast cancer and its aggressiveness in rats. For this study, we obtained 22‐days old female Sprague Dawley rats from Charles River (Wilmington, MA). Animals were divided into 5 groups, each containing 5 animals. Group 1 received standard AIN‐76A diet (Envigo – Teklad Diets, Madison, WI) containing 20% casein and 0% Hinute‐AM; Group 2 received the same diet containing 15% casein + 5% Hinute‐AM; Group 3 received the same diet, but containing 10% casein + 10% Hinute‐AM; Group 4 received the same diet but containing 5% casein + 15% Hinute‐AM; and Group 5 received the same diet but containing 0% casein + 20% Hinute‐AM. For induction of mammary tumors, all groups received a single intragastric administration of DMBA (Sigma Chemical Co., St. Louis) dissolved in sesame oil (80 mg/kg b.wt.) at 50 days of age. At 120 days post DMBA injection, the animals were euthanized by CO2 asphyxiation. All tumors were weighed and measured for volume, and a section of tumor was subjected to histological grading by a certified pathologist. Our preliminary data revealed that replacement of casein by Hinute‐AM as a source of dietary protein caused a dose‐dependent delay in the development of breast tumor, decrease in breast cancer incidence, a decrease in tumor volume, and tumor grade.Support or Funding InformationThis work was supported by grants from Fuji Oil Company, Osaka, Japan and by the Meharry Translational Research Center grant NIH 5U54MD007593

Ultra high temperature (UHT) processability of high protein dispersions prepared from milk protein-soy protein hydrolysate mixtures

This study investigated the effect of addition of soy protein hydrolysates on Ultra high temperature (UHT) processability of milk protein beverages. There is also a lack of reported data on UHT processability of soy protein hydrolysates. UHT processability of 80 g/kg protein reconstituted milk protein concentrate (8-RMPC), 80 g/kg protein soy protein hydrolysate (8-RSPH) and 8-RMPC with added 10, 20 and 30 g/kg protein RSPH (e.g. 8-RMPC+1-RSPH) was studied on a bench-top UHT equipment. Both 8-RMPC and 8-RSPH showed very high UHT processability (UHT plant run-time > 120 min). Inclusion of 1-RSPH in 8-RMPC did not affect UHT run-time (>120 min) and overall heat transfer coefficient (OHTC). Significant drop in OHTC was observed in 8-RMPC+2-RSPH without reducing the UHT run-time below 120 min mark and required UHT processing temperatures could be maintained (143–146 °C) throughout the UHT run. 8-RMPC+3-RSPH showed markedly reduced UHT processability both shorter UHT run-time (61 min) and very low OHTC values were observed which can be attributed to formation of larger protein aggregates. An increase in apparent viscosity (42.0 ± 0.6 and 11.8 ± 0.3 mPa s) for 8-RSMP+3-RSPH and 8-RSMP+2-RSPH, respectively) of UHT processed samples would have also induced severe fouling during UHT.

Influence of Protein Type on the Antimicrobial Activity of LAE Alone or in Combination with Methylparaben.

The cationic surfactant Lauric arginate (LAE) has gained approval for utilization in meat products (limit: 200 mg/kg). However, as for other antimicrobials, its activity is reduced when applied to complex food matrices. The current study therefore aims to better understand protein-antimicrobial agent-interactions and their influence on the antimicrobial activity of (i) LAE and (ii) methylparaben against Listeria innocua and Pseudomonas fluorescens in defined model systems (pH 6). Antimicrobials were utilized alone or in combination with nutrient broth containing either no protein or 2% bovine serum albumin, whey protein isolate, or soy protein hydrolysate. LAE was found to form complexes with all proteins due to electrostatic attraction, determined using microelectrophoretic and turbidity measurements. Minimal lethal concentrations of LAE were remarkably increased (4–13 fold) in the presence of proteins, with globular proteins having the strongest impact. Combinations of LAE (0–200 µg/mL) with the less structure-sensitive component methylparaben (approved concentration 0.1%) remarkably decreased the concentrations of LAE needed to strongly inhibit or even kill both, L. innocua and P. fluorescens in the presence of proteins. The study highlights the importance of ingredient interactions impacting microbial activity that are often not taken into account when examining antimicrobial components having different structure sensitivities.

Iron absorption stimulation by administration of soy protein hydrolysates containing bioactive peptides in rats

The prevalence of iron deficiency anemia in Indonesia is high. Most of the anemia is caused by iron deficiency syndrome due to inadequate iron intake and low bioavailability of iron sources. Some studies indicated that bioactive peptides from certain protein hydrolysates could support iron absorption. Our previous study showed that soy protein hydrolysates containing bioactive peptides indicated an iron-binding activity and could increase its solubility in water. Aim of this study was to investigate the effect of soy protein hydrolysates administration on iron serum levels in anemic Sprague Dawley rats. Anemia induction was performed by applying NaNO2 (0.5 mg/ml per 200 g body weight (BW) of rats per day for 14 days) orally. The experiment was carried out in a completely randomized design, consisting of six groups. The first group was the control normal group (N), without induction and the others were treatment groups that were induced with NaNO2 and supplemented with iron (0.3 mg/200 g BW), consisted of control group (CMC), control iron (Fe) group, iron and soy protein hydrolysate-1 (270 mg/200 g BW) (FeSH-1) group, iron and soy protein hydrolysate-2 (270 mg/200 g BW) (Fe-SH2) group and positive control iron vitamin C (0.24 mg/200 g BW) (Fe Vit. C) group. The result showed that Fe-SH2 treatment group had a better iron-binding capacity rather than other groups. This result suggests that soy protein hydrolysates could enhance iron absorption, which might be applied in human as a functional food to reduce anemia prevalence.

Iron absorption stimulation by administration of soy protein hydrolysates containing bioactive peptides in rats

The prevalence of iron deficiency anemia in Indonesia is high. Most of the anemia is caused by iron deficiency syndrome due to inadequate iron intake and low bioavailability of iron sources. Some studies indicated that bioactive peptides from certain protein hydrolysates could support iron absorption. Our previous study showed that soy protein hydrolysates containing bioactive peptides indicated an iron-binding activity and could increase its solubility in water. Aim of this study was to investigate the effect of soy protein hydrolysates administration on iron serum levels in anemic Sprague Dawley rats. Anemia induction was performed by applying NaNO2 (0.5 mg/ml per 200 g body weight (BW) of rats per day for 14 days) orally. The experiment was carried out in a completely randomized design, consisting of six groups. The first group was the control normal group (N), without induction and the others were treatment groups that were induced with NaNO2 and supplemented with iron (0.3 mg/200 g BW), consisted of control group (CMC), control iron (Fe) group, iron and soy protein hydrolysate-1 (270 mg/200 g BW) (FeSH-1) group, iron and soy protein hydrolysate-2 (270 mg/200 g BW) (Fe-SH2) group and positive control iron vitamin C (0.24 mg/200 g BW) (Fe Vit. C) group. The result showed that Fe-SH2 treatment group had a better iron-binding capacity rather than other groups. This result suggests that soy protein hydrolysates could enhance iron absorption, which might be applied in human as a functional food to reduce anemia prevalence.